This invention relates to an apparatus for refurbishing magnetic tape by removal of adherent and loose dirt from the tape.
Magnetic tape is extensively used as a means to magnetically record, store, and retrieve information for use in audio and digital-data applications. A particularly sensitive application is that wherein digital data is stored for use in the maintenance of computerized information systems. The tape so utilized should have a carefully monitored, preferably error-free, character. Even when the tape is not certifiably error-free, it is desirable that the number, and statistical distribution of errors be known so that particular tape can be matched to the requirements of particular information-storage applications.
When a tape is newly manufactured this data is readily obtainable using, for example, a tape-certifying apparatus available from Graham Magnetics Incorporated under the trademark Inspector IV. However, once a tape is used it becomes subject to error-inducing wear from contact with read and write heads, and it becomes subject to contamination with error-inducing debris or dirt. Some of the dirt is only loosely attached and is readily removable. Other dirt adheres to the surface from which it must be scraped. Thus, there have been developed such tape-cleaning apparatus as, for example, that described in U.S. Pat. No. 3,370,982 to Hayunga. That patent describes the use of scraper bars to remove dirt from tape being refurbished. Also known to the prior art is the use of a series of sharp edges formed about the periphery of apertures in thin metal sheet. The tape to be cleaned would be sucked into scraping contact with the metal sheet by vacuum.
A number of problems were presented by the prior art cleaning apparatus and processes. The scraping edges wore too quickly because of the abrading contact with, e.g., the iron-oxide-filled surface of the tape. Moreover, the cleaning and refurbishing action often was less effective at and near the edges of the tape than on the major area.
Consequently, the present inventor sought to provide an improved means to clean magnetic tape and other such web materials which require a scraping action.